Our research objective is to pursue our investigations of leukemia and cancer therapy by participation in Children's Cancer Study Group (CCSG). This organization is composed of pediatric hematologist/ oncologists, and is involved in protocol studies of pediatric malignancy, as formulated by the members of the group. The investigations include the drug and radiotherapy treatment of acute childhood leukemia in various stages and prophylactic and therapeutic trials in solid tumors of the young in conjunction with surgery and radiotherapy. Trials of immunotherapy in conjunction with chemotherapy in leukemia are also to be conducted. Data on the natural history, complications of treatment and the survival of these patients are collected on an ongoing basis. Statistical supervision is maintained in all of the protocol studies, and in most cases these studies are randomized to prevent bias.